Previous studies from this laboratory have revealed consistent, reproducible changes in the glycopeptide composition of surface membranes from transformed cells when compared with non-transformed, control cells. These changes involve most of the glycoproteins from every membrane systems of the cell. They may well be responsible for the altered behavior and invasive properties of the transformed cell. However, before the significance of such alterations can be understood, the glycoprotein involved in such fundamenal properties as cellular adhesion and morphological determination must be identified and characterized. Towards this end, a series of antisera have been developed which induce reversible rounding and detachment of the cell from its substratum. Using these antisera, we propose to: 1) identify the cell surface components involved in the maintenance of adhesion and morphology, 2) produce monospecific, monoclonal antibodies against those purified components using the hybridoma system, 3) isolate and characterize cellular mutants containing alterations in these surface components, and 4) begin detailed biochemical analysis of these individual components. These studies should allow our previous biochemical obstructions to be put in biological perspective.